Patterns of morphological, biochemical, and molecular evolution in the Oeneis chryxus complex (Lepidoptera : Satyridae): A test of historical biogeographical hypotheses

Surveys of allozyme allele frequency and mitochondrial DNA (mtDNA) sequence variation were employed to test historical biogeographical hypotheses on t he origin and unique distribution of the synchronized biennial, high-altitu de butterflies of the Oeneis chrysus complex in western North America. Popu lations of O. c. stanislaus and O. ivallda from the central and northern Si erra Nevada are indistinguishable by use of allozyme allele frequency data, possessed nearly identical mtDNA cytochrome oxidase subunit 1 (COI) haplot ypes, and were found to be relatively distantly related to O. c. chryxus fr om the Snake Range in eastern Nevada. However, individuals of O. ivallda fr om Piute Pass in the southern Sierra Nevada are more variable, with some in dividuals sharing mtDNA characteristics with O. c. chryxus. We find little support for the hypothesis proposed by W. Hovanitz in 1940 that O. e, stani slaus invaded the central Sierra Nevada from across the Great Basin and dis placed O. ivallda, but cannot reject the hypothesis that ancestral Oeneis d ispersed across the Great Basin to California, This result is congruent wit h hypotheses of dispersal across the Great Basin for the origin of some Sie rran alpine organisms. (C) 2001 Academic Press.